NAME
	  sigblock - Provides a	compatibility interface	to the sig-
	  procmask function

     LIBRARY
	  Standard C Library (libc.a)

     SYNOPSIS
	  int sigblock(
	       int mask	);

     PARAMETERS
	  mask Specifies the signals to	be added to the	set of signals
	       currently being blocked from delivery.

     DESCRIPTION
	  The sigblock() function causes the signals specified by the
	  mask parameter to be added to	the set	of signals currently
	  being	blocked	from delivery. The signals are blocked from
	  delivery by logically	ORing the mask parameter into the sig-
	  nal mask of the process.  Signal i is	blocked	if the i-th
	  bit in the mask parameter is a value of 1. Only signals with
	  values 1-31 can be masked with the sigblock()	function.

     NOTES
	  It is	not possible to	block SIGKILL. The system provides no
	  indication of	this restriction.

	  The sigblock() function is provided for compatibility	to
	  other	UNIX systems. Its function is a	subset of the sigproc-
	  mask() function.

     RETURN VALUES
	  On completion, the previous set of masked signals is
	  returned.

     RELATED INFORMATION
	  Functions: kill(2), sigaction(2), sigpause(3),
	  sigprocmask(2), sigsuspend(2), sigvec(2)